Type I collagen gel in seeding medium improves murine mesencymal stem cell loading onto the scaffold, increases their subsequent proliferation, and enhances culture mineralization.

Collagen I as a major organic component of bone matrix may be important for establishment and maintenance of mesenchymal stem cells (MSCs) in osteogenic 3D culture. To explore this subject, murine marrow-derived MSCs were seeded onto hybrid scaffolds of alginate/gelatin/beta-tricalcium phosphate in a medium either with or without collagen I gel. The cultures were then provided with osteogenic medium and incubated for three weeks during which loading efficiency, cell proliferation and the culture mineralization were quantified and statistically compared. According to the findings, in culture with collagen, although about 60% of the cells left the scaffolds, the remaining cells, however, proliferated extensively with a population doubling number (PDN) equivalent to 2.46 +/- 0.31 and organized as cell aggregations that were heavily mineralized (calcium concentration = 1.017 +/- 0.141 mM per scaffold), whereas in the culture without collagen, about 75% of the cells left the scaffolds, less cell proliferation occurred (PDN = 1.48 +/- 0.29) and no cell aggregation was observed. The calcium concentration in this culture was 0.185 +/- 0.029 mM per scaffold. All these differences were statistically significant (p < 0.001). Taken together, these data suggested that using the collagen I in seeding medium could help mMSCs loading into the scaffold, enhance their subsequent proliferation, and increase calcium deposition in 3D culture system.